lunes, 1 de septiembre de 2008

"Surely You're Joking, Mr. Feynman!"

Este es un extracto del libro mencionado arriba que se refiere la educación científica que vio en Brasil cuando, hace muchos años, estuvo en Brasil de sabático. Lo pongo aquí porque me da la impresión de que en México no estamos muy lejos de lo que el Dr. Feynman critica. Creo que su lectura puede ser una garan lección no sólo para los estudiantes sino también para los profesores. Para los que quieran leer el libro completo, que es sumamente interesante, la liga es:
http://www.gorgorat.com/

In regard to education in Brazil, I had a very interesting experience.
I was teaching a group of students who would ultimately become teachers,
since at that time there were not many opportunities in Brazil for a highly
trained person in science. These students had already had many courses, and
this was to be their most advanced course in electricity and magnetism Maxwell's equations, and so on.

The university was located in various office buildings throughout the
city, and the course I taught met in a building which overlooked the bay.
I discovered a very strange phenomenon: I could ask a question, which
the students would answer immediately. But the next time I would ask the
question -- the same subject, and the same question, as far as I could tell
-- they couldn't answer it at all! For instance, one time I was talking
about polarized light, and I gave them all some strips of polaroid.
Polaroid passes only light whose electric vector is in a certain
direction, so I explained how you could tell which way the light is
polarized from whether the polaroid is dark or light.
We first took two strips of polaroid and rotated them until they let
the most light through. From doing that we could tell that the two strips
were now admitting light polarized in the same direction -- what passed
through one piece of polaroid could also pass through the other. But then I
asked them how one could tell the absolute direction of polarization, for a
single piece of polaroid.
They hadn't any idea.
I knew this took a certain amount of ingenuity, so I gave them a hint:
"Look at the light reflected from the bay outside."
Nobody said anything.
Then I said, "Have you ever heard of Brewster's Angle?"
"Yes, sir! Brewster's Angle is the angle at which light reflected from
a medium with an index of refraction is completely polarized."
"And which way is the light polarized when it's reflected?"
"The light is polarized perpendicular to the plane of reflection, sir."
Even now, I have to think about it; they knew it cold! They even knew the
tangent of the angle equals the index!
I said, "Well?"
Still nothing. They had just told me that light reflected from a medium
with an index, such as the bay outside, was polarized; they had even told me
which way it was polarized.
I said, "Look at the bay outside, through the polaroid. Now turn the
polaroid."
"Ooh, it's polarized!" they said.
After a lot of investigation, I finally figured out that the students
had memorized everything, but they didn't know what anything meant. When
they heard "light that is reflected from a medium with an index," they
didn't know that it meant a material such as water. They didn't know that
the "direction of the light" is the direction in which you see something
when you're looking at it, and so on. Everything was entirely memorized, yet
nothing had been translated into meaningful words. So if I asked, "What is
Brewster's Angle?" I'm going into the computer with the right keywords. But
if I say, "Look at the water," nothing happens -- they don't have anything
under "Look at the water"!
Later I attended a lecture at the engineering school. The lecture went
like this, translated into English: "Two bodies... are considered
equivalent... if equal torques... will produce... equal acceleration. Two
bodies, are considered equivalent, if equal torques, will produce equal
acceleration." The students were all sitting there taking dictation, and
when the professor repeated the sentence, they checked it to make sure they
wrote it down all right. Then they wrote down the next sentence, and on and
on. I was the only one who knew the professor was talking about objects with
the same moment of inertia, and it was hard to figure out.
I didn't see how they were going to learn anything from that. Here he
was talking about moments of inertia, but there was no discussion about how
hard it is to push a door open when you put heavy weights on the outside,
compared to when you put them near the hinge -- nothing!
After the lecture, I talked to a student: "You take all those notes --
what do you do with them?"
"Oh, we study them," he says. "We'll have an exam."
"What will the exam be like?"
"Very easy. I can tell you now one of the questions." He looks at his
notebook and says, " 'When are two bodies equivalent?' And the answer is,
'Two bodies are considered equivalent if equal torques will produce equal
acceleration.' " So, you see, they could pass the examinations, and "learn"
all this stuff, and not know anything at all, except what they had
memorized.
Then I went to an entrance exam for students coming into the
engineering school. It was an oral exam, and I was allowed to listen to it.
One of the students was absolutely super: He answered everything nifty! The
examiners asked him what diamagnetism was, and he answered it perfectly.
Then they asked, "When light comes at an angle through a sheet of material
with a certain thickness, and a certain index N, what happens to the light?"
"It comes out parallel to itself, sir -- displaced."
"And how much is it displaced?"
"I don't know, sir, but I can figure it out." So he figured it out. He
was very good. But I had, by this time, my suspicions.
After the exam I went up to this bright young man, and explained to him
that I was from the United States, and that I wanted to ask him some
questions that would not affect the result of his examination in any way.
The first question I ask is, "Can you give me some example of a diamagnetic
substance?"
"No."
Then I asked, "If this book was made of glass, and I was looking at
something on the table through it, what would happen to the image if I
tilted the glass?"
"It would be deflected, sir, by twice the angle that you've turned the
book."
I said, "You haven't got it mixed up with a mirror, have you?"
"No, sir!"
He had just told me in the examination that the light would be
displaced, parallel to itself, and therefore the image would move over to
one side, but would not be turned by any angle. He had even figured out how
much it would be displaced, but he didn't realize that a piece of glass is a
material with an index, and that his calculation had applied to my question.
I taught a course at the engineering school on mathematical methods in
physics, in which I tried to show how to solve problems by trial and error.
It's something that people don't usually learn, so I began with some simple
examples of arithmetic to illustrate the method. I was surprised that only
about eight out of the eighty or so students turned in the first assignment.
So I gave a strong lecture about having to actually try it, not just sit
back and watch me do it.
After the lecture some students came up to me in a little delegation,
and told me that I didn't understand the backgrounds that they have, that
they can study without doing the problems, that they have already learned
arithmetic, and that this stuff was beneath them.
So I kept going with the class, and no matter how complicated or
obviously advanced the work was becoming, they were never handing a damn
thing in. Of course I realized what it was: They couldn't do it!
One other thing I could never get them to do was to ask questions.
Finally, a student explained it to me: "If I ask you a question during the
lecture, afterwards everybody will be telling me, 'What are you wasting our
time for in the class? We're trying to learn something. And you're stopping
him by asking a question'."
It was a kind of one-upmanship, where nobody knows what's going on, and
they'd put the other one down as if they did know. They all fake that they
know, and if one student admits for a moment that something is confusing by
asking a question, the others take a high-handed attitude, acting as if it's
not confusing at all, telling him that he's wasting their time.
I explained how useful it was to work together, to discuss the
questions, to talk it over, but they wouldn't do that either, because they
would be losing face if they had to ask someone else. It was pitiful! All
the work they did, intelligent people, but they got themselves into this
funny state of mind, this strange kind of self-propagating "education" which
is meaningless, utterly meaningless!
At the end of the academic year, the students asked me to give a talk
about my experiences of teaching in Brazil. At the talk there would be not
only students, but professors and government officials, so I made them
promise that I could say whatever I wanted. They said, "Sure. Of course.
It's a free country."
So I came in, carrying the elementary physics textbook that they used
in the first year of college. They thought this book was especially good
because it had different kinds of typeface -- bold black for the most
important things to remember, lighter for less important things, and so on.
Right away somebody said, "You're not going to say anything bad about
the textbook, are you? The man who wrote it is here, and everybody thinks
it's a good textbook."
"You promised I could say whatever I wanted."
The lecture hall was full. I started out by defining science as an
understanding of the behavior of nature. Then I asked, "What is a good
reason for teaching science? Of course, no country can consider itself
civilized unless... yak, yak, yak." They were all sitting there nodding,
because I know that's the way they think.
Then I say, "That, of course, is absurd, because why should we feel we
have to keep up with another country? We have to do it for a good reason, a
sensible reason; not just because other countries do." Then I talked about
the utility of science, and its contribution to the improvement of the human
condition, and all that -- I really teased them a little bit.
Then I say, "The main purpose of my talk is to demonstrate to you that
no science is being taught in Brazil!"
I can see them stir, thinking, "What? No science? This is absolutely
crazy! We have all these classes."
So I tell them that one of the first things to strike me when I came to
Brazil was to see elementary school kids in bookstores, buying physics
books. There are so many kids learning physics in Brazil, beginning much
earlier than kids do in the United States, that it's amazing you don't find
many physicists in Brazil -- why is that? So many kids are working so hard,
and nothing comes of it.
Then I gave the analogy of a Greek scholar who loves the Greek
language, who knows that in his own country there aren't many children
studying Greek. But he comes to another country, where he is delighted to
find everybody studying Greek -- even the smaller kids in the elementary
schools. He goes to the examination of a student who is coming to get his
degree in Greek, and asks him, "What were Socrates' ideas on the
relationship between Truth and Beauty?" -- and the student can't answer.
Then he asks the student, "What did Socrates say to Plato in the Third
Symposium?" the student lights up and goes, "Brrrrrrrrr-up" -- he tells you
everything, word for word, that Socrates said, in beautiful Greek.
But what Socrates was talking about in the Third Symposium was the
relationship between Truth and Beauty!
What this Greek scholar discovers is, the students in another country
learn Greek by first learning to pronounce the letters, then the words, and
then sentences and paragraphs. They can recite, word for word, what Socrates
said, without realizing that those Greek words actually mean something. To
the student they are all artificial sounds. Nobody has ever translated them
into words the students can understand.
I said, "That's how it looks to me, when I see you teaching the kids
'science' here in Brazil." (Big blast, right?)
Then I held up the elementary physics textbook they were using. "There
are no experimental results mentioned anywhere in this book, except in one
place where there is a ball, rolling down an inclined plane, in which it
says how far the ball got after one second, two seconds, three seconds, and
so on. The numbers have 'errors' in them -- that is, if you look at them,
you think you're looking at experimental results, because the numbers are a
little above, or a little below, the theoretical values. The book even talks
about having to correct the experimental errors -- very fine. The trouble
is, when you calculate the value of the acceleration constant from these
values, you get the right answer. But a ball rolling down an inclined plane,
if it is actually done, has an inertia to get it to turn, and will, if you
do the experiment, produce five-sevenths of the right answer, because of the
extra energy needed to go into the rotation of the ball. Therefore this
single example of experimental 'results' is obtained from a fake experiment.
Nobody had rolled such a ball, or they would never have gotten those
results!
"I have discovered something else," I continued. "By flipping the pages
at random, and putting my finger in and reading the sentences on that page,
I can show you what's the matter -- how it's not science, but memorizing, in
every circumstance. Therefore I am brave enough to flip through the pages
now, in front of this audience, to put my finger in, to read, and to show
you."
So I did it. Brrrrrrrup -- I stuck my finger in, and I started to read:
"Triboluminescence. Triboluminescence is the light emitted when crystals are
crushed..."
I said, "And there, have you got science? No! You have only told what a
word means in terms of other words. You haven't told anything about nature
-- what crystals produce light when you crush them, why they produce light.
Did you see any student go home and try it? He can't.
"But if, instead, you were to write, 'When you take a lump of sugar and
crush it with a pair of pliers in the dark, you can see a bluish flash. Some
other crystals do that too. Nobody knows why. The phenomenon is called
"triboluminescence." ' Then someone will go home and try it. Then there's an
experience of nature." I used that example to show them, but it didn't make
any difference where I would have put my finger in the book; it was like
that everywhere.
Finally, I said that I couldn't see how anyone could be educated by
this self-propagating system in which people pass exams, and teach others to
pass exams, but nobody knows anything. "However," I said, "I must be wrong.
There were two Students in my class who did very well, and one of the
physicists I know was educated entirely in Brazil. Thus, it must be possible
for some people to work their way through the system, bad as it is."
Well, after I gave the talk, the head of the science education
department got up and said, "Mr. Feynman has told us some things that are
very hard for us to hear, but it appears to be that he really loves science,
and is sincere in his criticism. Therefore, I think we should listen to him.
I came here knowing we have some sickness in our system of education; what I
have learned is that we have a cancer!" -- and he sat down.
That gave other people the freedom to speak out, and there was a big
excitement. Everybody was getting up and making suggestions. The students
got some committee together to mimeograph the lectures in advance, and they
got other committees organized to do this and that.
Then something happened which was totally unexpected for me. One of the
students got up and said, "I'm one of the two students whom Mr. Feynman
referred to at the end of his talk. I was not educated in Brazil; I was
educated in Germany, and I've just come to Brazil this year."
The other student who had done well in class had a similar thing to
say. And the professor I had mentioned got up and said, "I was educated here
in Brazil during the war, when, fortunately, all of the professors had left
the university, so I learned everything by reading alone. Therefore I was
not really educated under the Brazilian system."
I didn't expect that. I knew the system was bad, but 100 percent -- it
was terrible!
Since I had gone to Brazil under a program sponsored by the United
States Government, I was asked by the State Department to write a report
about my experiences in Brazil, so I wrote out the essentials of the speech
I had just given. I found out later through the grapevine that the reaction
of somebody in the State Department was, "That shows you how dangerous it is
to send somebody to Brazil who is so naive. Foolish fellow; he can only
cause trouble. He didn't understand the problems." Quite the contrary! I
think this person in the State Department was naive to think that because he
saw a university with a list of courses and descriptions, that's what it
was.

6 comentarios:

Marian dijo...

Gracias por subir este tipo de notas, me son útiles... hay veces que caigo en la monotonía y el hacer las cosas mecánicamente ... es bueno leer algo así para despertar un poco la conciencia.

HaB dijo...

De esto surge la necesidad de aplicar "learning by doing". Lo que está muy descuidado en nuestro Posgrado, al menos como un sistema de enseñar a pensar.

Angel dijo...

"Inventando la Ciencia"
Angel Figueroa Soto


Basado en el extracto del libro:
"Surely You're Joking, Mr. Feynman!"

En el extracto del libro "Surely You're Joking, Mr. Feynman!" se refleja toda una tradición de enseñanza (en particular en ciencias) en México. Se enseña a aceptar dogmas científicos, donde la memorización, la aceptación de “leyes generales” y el orgullo son las herramientas mínimas para que los estudiantes y docentes intenten entender y enseñar la ciencia en un circulo vicioso al que llamamos el proceso enseñanza-aprendizaje.

Es una realidad que los estudiantes de distintos niveles están inmersos en lo que Feynman llama “self-propagating system”. Esto se refiere a un sistema donde el objetivo es encontrar la metodología para acreditar las materias y una vez desarrollada, enseñar a otros como es dicho método. Este método no necesariamente implica un aprendizaje constructivo en los estudiantes, sin embargo cumplen el “principal objetivo” que es la acreditación del curso o materia.

Es practica común entre los estudiantes el memorizar y tomar como verdad lo ya estipulado, como un dogma de fe pre-existente en la ciencia. Sin embargo “todo lo dicho, es dicho por alguien” , este aforismo refleja una idea central: los dogmas en la ciencia no existe, las definiciones, las “leyes” y en general todo el aparato matemático del que nos valemos no es mas que una invención del hombre para intentar dar una explicación a los fenómenos que observamos en la naturaleza. Si nos damos cuenta que la ciencia no es sino una invención, no deberíamos aceptar dogmas pero si construir nuestro propio conocimiento.

Personalmente, considero que en México el sistema educativo debe valorar la posibilidad de cambiar la concepción conductista de la ciencia, ya que es la responsable de “educar” y “enseñar” de una manera completamente rígida y sin discutir o poner a juicio lo “ya dicho”. Deberíamos preguntarnos si ¿Realmente estamos educando?, ¿que estamos aprendiendo? O todo es un ciclo de memorización en el cual se define la acción acreditar solo si el alumno logra repetir de manera precisa los “conocimientos”. Es posible constatar los prejuicios que los alumnos traen consigo a las clases de física y matemáticas, que han sido consideradas como materias “difíciles” y sin una aplicación real, donde muchas veces la memoria es la principal herramienta de estudio y se olvida el significado de las expresiones y métodos de la lógica.

Enseñando y haciendo ciencia de manera constructiva, estaríamos logrando que el ciclo enseñanza-aprendizaje sea un constructor de conocimiento, donde todos aprendemos a aprender, dejando atrás los dogmas, valorando el significado de fondo de cada uno de lo que hemos denominado “modelos” o “leyes” y no ver estas leyes como un fin ultimo o como un dogma científico, sino como una invención de lo que hemos denominado ciencia.

Ramón dijo...

Este verdaderamente es un serio problema que compartimos con los brasileños de esa época (quiero pensar que la cosa ha mejorado desde entonces por allá). También se refleja en los índices de educación tan pobres de nuestro país.
Un problema al que me he enfrentado en muchas ocasiones es cuando he tratado de explicar el porqué de alguna fórmula física o matemática, encontrando que los alumnos se desesperan porque no "llego al grano". En este caso el "grano" es decirles (que no enseñarles) cómo se aplica la mencionada fórmula o ecuación. Varias veces me han increpado diciendo "No nos interesa de dónde viene, sólo queremos saber cómo se usa". Esto proviene del hecho de que los alumnos están acostumbrados no a pensar sino a emplear "recetas". Esta también es una de las causas por las que los alumnos detestan las matemáticas. Sólo se les ha enseñado a "mecanizar" operaciones y esto, como todos sabemos, es tedioso y aburrido. Tenemos que cambiar el sistema desde abajo pero también desde arriba.

paulina patiño dijo...

El problema descrito por Feyman es una realidad en México, lo cual me llama extremadamente la atención. En México no es un secreto que la educación anda mal pero poco se sabe es cuanto repercute y a que niveles.

Una de las razones por la cual decidí estudiar una maestría es que realice un verano de investigación el cual me gusto mucho por la acción del pensar y tener una libertad sobre mis pensamientos. Es difícil de explicar para mi, pero es una manera muy personal de medir y/o sentir una libertad individual.

Concuerdo con Marian que es importante leer estos artículos para no caer en la monotonía de todos los días, perder la esencia misma de la investigación y del cuestionamiento diario sobre lo que se vaya aprendiendo o descubriendo en día con día.

Anónimo dijo...

Estimado amigo

¿Por qué no recomiendas el libro en su edición en hermosa lengua española?
Hace ya veinte años leí ¿Está Vd. de broma Sr. Feynman? de Alianza Editorial, Madrid, 1987, y confieso que disfruté mucho haciéndolo.

Desgraciadamente en España tenemos los mismos problemas con la enseñanza de la física que los brasileños y, por lo que estoy leyendo, que los mexicanos.

Desde España, con afecto.

C. Armesto